Here's what rhymes with semiinvariant.
variant invariant Words that almost rhyme with semiinvariant
cerement hairiest chariot heaviest recreant veriest lariat scariest cheviot wariest teariest prescient pettiest sexiest sketchiest fleshiest heftiest fleshliest peppiest sweatiest tetchiest zestiest leggiest wealthiest commissariat deadliest lengthiest smelliest dressiest stealthiest peskiest stretchiest testiest preppiest secretariat friendliest homeliest cleanliest comeliest unfriendliest uncleanliest proletariat